_Range._--Washington from the Cascades west; southwestern British Columbia west of 120° W Longitude north to Lund.
_Diagnosis._--Size medium for the species; average and extreme measurements of 20 specimens from the Olympic Mountains, Washington, are: total length, 117.3 (107-125); tail, 49.8 (41-54); hind foot, 13.4 (12-14). Color dark in both summer and winter.
_Comparisons._--For comparison with _permiliensis_ see account of that subspecies. Darker, longer-tailed, and somewhat larger cranially than _S. v. obscurus_ with which it intergrades in southwestern British Columbia. Smaller in all dimensions, but much the same color as _S. v. longicauda_ with which it intergrades along the British Columbian coast north of Lund. Larger, darker, less reddish, and longer-tailed than the sympatric _S. v. vagrans_.
_Remarks._--_S. v. setosus_ lives mostly in forests. According to Dalquest (1948:139) it is commonest at high altitudes in western Washington. In the Hudsonian Life-zone where shrew habitat is more restricted and marginal than it is at lower altitudes in the humid part of Washington, _setosus_ might be expected to compete with _S. v. vagrans_ and to supplant it. Records of occurrence in the Olympic Mountains suggest a degree of such separation there.
_Specimens examined._--Total number, 135.
BRITISH COLUMBIA: Lund, Malaspina Inlet, 4 BS; Gibson's Landing, 10 BS; Port Moody, 19 BS; Langley, 2 BS; Chilliwack, 1 BS; Manning Park, 2 PMBC.
WASHINGTON: _Whatcom Co._: Mt. Baker, 6 WSC; Barron, 1 BS. _Chelan Co._: Clovay Pass, 1 WSC; Stehekin, 6 (4 WSC, 2 BS); Cascade Tunnel, 1 WSC. _King Co._: Scenic, 1 WSC. _Kittitas Co._: Lake Kachess, 1 WSC; Easton, 10 BS. _Clallam Co._: 8 mi. W Sekin River, 1 WSC; mouth of Sekin River, 1 WSC; Clallam Bay, 1 CMNH; 7 mi. W Port Angeles, 1 WSC; Ozette Lake, 1 CMNH; 12 mi. S Port Angeles, 4 WSC; Forks, 1 CMNH; Deer Lake, 7 CMNH; Hoh Lake, 1 CMNH; Bogachiel Peak, 1 CMNH; Sol Duc Hot Springs, 3 CMNH; Sol Duc Park, 1 CMNH; Canyon Creek, 1 WSC; Sol Duc Divide, 2 WSC; Cat Creek, 2 WSC. _Jefferson Co._: Jackson Ranger Station, 1 CMNH; Mt. Kimta, 2 CMNH; Reflection Lake, 6 CMNH; Blue Glacier, 3 CMNH. _Gray's Harbor Co._: Westport, 1 WSC. _Pierce Co._: Fort Lewis, 1 FC; Mt. Rainier, 19 (16 BS, 3 WSC). _Pacific Co._: Tokeland, 2 BS. _Yakima Co._: Gotchen Creek, 3 WSC; Mt. Adams, 1 WSC. _Skamania Co._: Mt. St. Helens, 1.